:
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
26
DIAGNOSIS AND SOLUTION (CONT)
Indoor and outdoor unit communication error (EL01)
Description:
The indoor unit has not received feedback from the outdoor unit for 150 seconds, four consecutive times.
Recommended parts to prepare:
• Indoor PCB
•
Outdoor PCB
• Short-circuited component
Troubleshooting and repair
Does the error code
still appear?
Power off, then restart the unit after 2
minutes.
Measure the DC voltage between N/L2
and S (Black pin to N/L2, Red pin to S).
The value is fixed
and close to 0.
The value is alternative
from negative to positive.
The value is always positive.
Check the wiring
connection between the
indoor and outdoor unit.
Is the connection good?
Check the wiring connection
from the outdoor terminal to
the outdoor PCB and the wiring
between the PCBs ( if there is
more than 1 PCB).
Check the wiring connection
from the indoor terminal
to the indoor PCB.
Are they good?
Turn on the unit, check if W
and 1(L) are connected?
Check if the power LED is
on?
No
Yes
Yes
Unplug all the high voltage
components connected to main
PCB such as 4 way valve, heater,
AC fan one by one to check their
resistance. Is there any component
short circuit?
Unplug the electronic expansion valve.
Check if power LED is on?
No
No
Check the AC voltage of the L, N
output to the IPM board. Is it
the same as the power input?
Check the DC 5V, 12V
from IPM board to main
PCB, are they normal?
Unplug all the high voltage
components connected to main
PCB such as 4 way valve, heater,
AC fan one by one to check their
resistance. Is there any component
short circuit?
Yes
No
Unplug the electronic expansion
valve. Check if the DC 5V, 12V
to the main PCB is OK.
Replace the short-circuited
component and the main PCB.
Replace the coil of the
electronic expansion valve.
Replace the outdoor PCB.
Replace the short
circuited component and
the outdoor PCB.
Yes
Yes
Yes
Yes
Replace the
main PCB.
No
Yes
No
Replace the IPM board.
No
Replace the
indoor PCB.
No
Issue is solved.
Correct the connection or
replace the wires.
No
Yes
Yes
For units with main PCB and IPM board
both
For units with only one
PCB
For units
with W wire
For units without W
wire
No
